LITTLE ROCK — Arkansas Gov. Mike Beebe says his office's preliminary research suggests a proposal to ban most abortions in the state is unconstitutional but isn't ready to say whether he opposes the legislation.

Beebe said Monday his office is still researching the legality of the proposal to ban most abortions if a heartbeat is detected but said the early research suggests it would have constitutional problems. The Senate last week approved the measure, which would ban abortions as early as six weeks into a pregnancy.

Beebe said his office is also researching the legality of two other abortion measures. One would ban abortions at 20 weeks into a pregnancy and the other would ban insurers in the exchange created under the federal health care law from covering abortions.